Turbine, compressor, or like rotary machine having a pivoted indicator blade responsive to operating conditions



May 4, 1954 W. E. P. JOHNSON TURBINE, COMPRESSOR, OR LIKE ROTARY MACHINEHAVING A PIVOTED INDICATOR BLADE RESPONSIVE TO OPERATING CONDITIONSFiled Dec. 2?, 194a 2 Sheets-Sheet 1 Fig. 2 9 O 6 4 May 4, 1954 w. E. P.JOH ON 2,677,273 TURBINE, COMPRESSO 0 L ROT MACH HAVING A PIVOTED I DCATOR LADE E PONSI TO OPERA co TIO Filed Dec. 27, 1948 2 Sheets-Sheet 2J5 .4770 NEYS Patented May 4, 1954 DICATOR BLADE RESPONSIVE T O OPER-ATING CONDITIONS William Evelyn Patrick Johnson, Hampstead,

London, England, assignor to Power Jets (Research and Development)England, a British company Limited, London,

I Application December 27, 1948, Serial No. 67,406

Claims priority, application Great Britain January 7, 1948 Thisinvention relates to bladed rotary fluid.- flow machines, such asturbines or compressors, and is primarily concerned with machines inwhich the fluid-flow is in the axial direction.

One object of the invention is to afford means adapted to respond toanoperating condition of the machine, and either to give an indication ofvariations in such operating condition, or to influence the operation ofcontrol means in accordance with such variations.

With this object in view the invention in its broad scope provides abladed rotary fluid-flow machine such as a compressor or turbinecomprising a stationary structure, in part defining a fluid flow passagethrough the machine, a row of stator blades supported by the saidstructure and disposed across the passage, a pivot mounting for at leastone of the said stator blades, the axis of pivoting extending in thegeneral direction of the machine axis, further mounting meansforsecurely holding the remaining blades, an extension of the saidmovable blade beyond the confine of the passage, and an element abuttingthe said extension and resiliently opposing movement of the saidextension, which element is operable to initiate an external indicationof the extent of the said movement, whereby a reading proportional tothe fluid forces acting. on the movable blade is obtainable.

The invention may be used to indicate the torque of a turbine (orcompressor) and therefore the power delivered or absorbed by integration with R. P. M.

For the sake of example, two constructional embodiments of the inventionwill now be described in greater detail with reference to theaccompanying diagrammatic drawings, in which:

Figure 1 is a fragmentary transverse section through an axial flowturbine according to a first embodiment.

Figure 2 is a section on the line II-II in Figure 1.

Figure 3 is a similar view to Figure 1, but showing the secondembodiment.

Figure 4 is a section on the line IV-IV of Figure 3.

In the construction shown in Figures 1-2. the casing I of an axial flowturbine carries stator blades, of which only one row is shown. of thatrow one blade 2 is pivotally mounted on an axis parallel to that of theturbine, while the remaining blades 3 are fixed.

That part of the turbine casing adjacent the row of stator blades showncomprises a pair of annuli 4, 5, secured in abutting relationship to 6Claims. Cl. 73-133) each other, and to the remainder of the casing'I,

by suitable axial bolts (not shown). The annuli 4', 5, are formed withcomplementary recesses 5,

I, which co-operate to form an opening in which the blade 2 is pivotallysuspended by a pin 8, and

needle bearings 9. The blade 2 is provided with an outward lever armextension I0 connected to a suitably-supported piezo-electric pressureelement I I forming part of an electrical circuit indil0 cated generallyby I2 and which includes an electrical indicating device I3 of anysuitable known type.

The tangential component of fluid force on the blade 2 causes slightmovement of the blade about its pivot, resulting in deformation of thepiezoelectric element II by thelever arm l0, thus in known mannergenerating in the circuit I2 an E. M. F. which produces at theindicating device I3 a'response proportional to the angulardisplacement-ofthe blade due to the tangentialcomponent of fluid force.This latter, being proportional to the reaction in the blade-row, is ameasure of torque.

To seal a leakage of Working fluid at theblade' pivot a chamber I4. isprovided enclosing the lever arm I0 and associated parts.

It is desirable for the .pivot' of the blade to be; so constructed thatthe internal surface of the fluid passage of the machine is asuninterrupted as is possible, and leakage offluid at'the actual" pivotis reduced to a minimum. To this end the" pivot may, if preferred, beformed by arcuate surfaces at the blade root and complementary surfacesin the casing, as in the construction hereinafter described withreference to Figures 3 and 4.

If desired there may be more than one pivoted blade in a row, or one ormore pivoted blades in successive rows. In these latter cases themeasuring blades may be commonly connected to one indicator.

In the embodiment shown in Figures 3 and 4 pivotally movable statorblade I5 is secured in the abutting annuli I9, 20 which constitute partof the stator casing and are held together and to the remaining part ofthe stator casing by axial bolts (not shown). Arcuate surfaces I6 on theroot portion of the blade I5 cooperate with corresponding arcuatesurfaces formed in the recesses II, I8 provided in the annuli I9, 20.The blade I5 has a lever arm extension l0 which, as in the previousexample, is connected to a suitably supported piezo-electric element IIforming part of an electric circuit indicated generally by I2 andincluding an electric indieating device l3, As in the previous examplethe lever. armfilflxis housed in. a chamber H so as to sealany workingfluid which may have leaked between the cooperating surfaces at theblade root.

As before the tangential component of fluid force on the blade l5causes' deformati'on of the for at least one of the said stator blades,the

axis of pivoting extending in the general direction of the machine axis,mounting means for securely holding the remaining blades of the saidrow, a chamber external to; thercasing and :posi tioned .inalignment-with"the said pivctable blade, alever arm on said pivotabl eblade extendingbeyond said pivot mounting into said chamber,

and an element supported within the chamberabutting the said zlever armfor opposing resiliently movement of: the said lever arm and.

operable to produce electric Signals which vary in proportionto thelever arm movement, and an electric circuit connected to-said elementfor transmission of said signals, whereby signals proportional to fluidforces acting on said pivota-ble blade-are obtained;

2. A bladed rotary fluid flow machine as claimed'in claim '1'andicomprising an indicator in said circuit bymeans of" which earlingsof torque 'acting upon said pivotable blade are directly obtained.

'3. A bladed. roan-y fluid flow machine as: claimed in claim 1" and:comprising arcuate sur-- faces-a1; the root of said pivotable blade andcomplementary surfaces,- to-said arcuate surfaces formed in said casingso as to cooperate togethertoform said pivot-mounting.

4'. A bladed rotary fluid flow machine asclaimed in claim 1 in whichsaid-stationary casing comprisestwoabutting annuli and complementaryrecesses in the abutting iaces' ofsaid annuli together forming. anapertu're through the casing, and in which the pivot mounting for saidpivotableblad'e comprises a needle bearing within the blade-and-a pinpassing through said bearing and "extending across said aperture.

5,. Aibladedrntary fluid flowumachine such as a compressor or turbinecomprising a stationary casing, in .part' defining an axially-extendingfluid flowpassage through themachine, a row-of stator blades mountedinside said casing and disposed across said passage, a pivot mountingfor at least one oi said stator blades, the axis of pivotingextending'in the general direction of the machineaxis, mounting meansfor securely holding theremaining blades of the said row, a chamberexternal to the casing and positioned in alignment with thesaidpivotable blade, a lever arm on said pivotalaleblade extendingbeyond said pivot mounting into said chamber, a piezoelectric crystalelement supported Within the chamber and abutting said lever arm so asto prevent more than limited movement of said leverarm and an electriccircuit connected to said element for transmission of signalstherefrom-which are proportional to the deformation of the element bylever arm movement, whereby signals proportional itofluidforces actingon said pivotable blade are. obtained.

6. A'bladed rotaryfiuid'flow machine such as a compressor or turbinecomprising a stationary the passage, a pivot mounting for at least oneof the said stator blades, the axis of pivoting extending in the generaldirection of the ma-- chine-axis, further mounting means for securelyholding the remaining blades, an extension of the said movable bladebeyond the confine of' the passage, and an elementabuttingthe saidextension andresilientlyopposing movement of the-said extension, whichelement is operable toinitiate an externalindica-tion of, the extent ofthe. said movement, whereby a. reading proportional to the fluid forces:acting on the 'movable blade is obtainable.-

- Number Name Date 1,401,668 Brown et a1 Dec. 27, 1921 2,014,684 JunkersSept. 1'7, 1935 2,173,382 West Sept. 19,1939 2,311,684 Okamura et a1Feb. 23, 1943 2,378,958v Troller June 26, 1945' 2,388,208 Foss Oct. 130,1945. 2,409,837 Alford Oct. 22, 1946; 2,460,778 'Willgoos Feb..1, 19492,477,954 Blanc Aug. .2, 1949

